export function createVNode(vm, tag, key, data, children, text) {
  return {
    vm,
    tag,
    key,
    // 就是属性
    data,
    children,
    text
  }
}
export function createVElement(vm, tag, attrs, ...children) {
  if (attrs) {
    var { key } = attrs
    delete attrs.key
  }
  return createVNode(vm, tag, key, attrs, children)
}
export function createVTextNode(vm, content) {
  return createVNode(vm, undefined, undefined, undefined, undefined, content)
}